ww/test/wcc/915_arr_module_index_run.c

/*
 * 915_arr_module_index_run — runtime + byte-id net for #128b: a
 * cross-package indexed read on an imported global `let arr: [N]T`
 * (the `mod.arr[i]` shape) must compute the array's ADDRESS via LEAQ
 * and stride by the element type's size. Pre-fix both stages
 * mis-compiled this shape, but differently:
 *   - cstage: emitted `MOVQ mod.arr(SB), AX` (loaded the first 8 bytes
 *     of the array as if it were a pointer-var value), then ADDed the
 *     index, then MOVZBQ at that junk address — SEGFAULT-class memory
 *     corruption on any non-trivial index. cstage also defaulted esz=1
 *     (the `bt = n->lhs->type` was NULL for SK_USE module idents).
 *   - wwstage: had the same MOVQ-not-LEAQ bug; in earlier session
 *     state also defaulted esz=8 + MOVQ-load (wrong stride + wrong
 *     load-width). By the time #128b ratified, wwstage was emitting
 *     IMUL$2 + MOVZWQ correctly (via stamped n.type_ path) but the
 *     base load remained MOVQ-not-LEAQ.
 *
 * Fix (per the design's option B — use-site at cgindex/cgassign, NOT
 * a provider-shape change at cgdot):
 *   - cstage: extend `cg_dotbase_addr` (the #135 helper) to recognise
 *     module-imported `let X: [N]T` and emit `LEAQ X(SB)` for the
 *     base. Add a `let_var_type(name)` lookup (LetVar gains a `type`
 *     field) so cgindex's N_INDEX case can fall back to the imported
 *     let's type when `n->lhs->type` is NULL (SK_USE-bound ident).
 *   - wwstage: extend `dotbaseaddr` parallel — when the inner ident
 *     isn't a local (localfindnode → nil) but `letvartnode(base.str)`
 *     resolves to N_TARRAY, emit `LEAQ symname(SB)`.
 *
 * Rule-10 alignment: both stages share the same cgindex N_INDEX
 * fallback shape; the helper is the use-site fix per #135's pattern,
 * preserving cgdot's current MOVQ semantics so whole-array-assign
 * shapes (defensive case; not exercised in committed code per
 * design-pass audit) aren't disturbed.
 *
 * Each row carries a `ww build` + run asserting the exit code (the
 * cstage-segfault repro now exits cleanly). Single-file rows also carry
 * a w6c vs w6c_ww `.s` cmp (rule-10 byte-id); the cross-package module
 * rows gate on runtime exit here and are byte-id-covered cross-package
 * by 994. The probe table is a test-local exported `[8]u16` (package
 * wcmodarr — see the #93 retarget note below; it replaced strconv's
 * private `let left_shift_table`, which separate compilation correctly
 * hides).
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>

static int
runwait(const char *cmd)
{
	int rc = system(cmd);
	if (rc == -1) return -1;
	if (WIFEXITED(rc)) return WEXITSTATUS(rc);
	return -1;
}

struct row {
	const char *label;
	const char *src;	/* main.ww content */
	const char *modname;	/* exported-probe-table package, or NULL */
	const char *modsrc;	/* that package's content, or NULL */
	int want_exit;
};

/* #93 (915 encapsulation retarget, ken-t): the module rows used to read
 * strconv's PRIVATE `let left_shift_table` — which separate compilation
 * CORRECTLY hides (the combined path only "worked" because the private
 * symbol leaked into one unit). Retargeted to a test-LOCAL package that
 * EXPORTS its own probe table: the same cross-package `mod.arr[i]` cgen
 * shape (LEAQ base + element-size stride, #128b), encapsulation-faithful
 * and sep-linkable. (The deeper checker tighten — loud-reject a cross-pkg
 * private ref — is tracked as #45; NOT attempted here.) Table prefix is
 * the same u16 sequence strconv used, so the expected exits are unchanged
 * (idx0→0, idx2→0x0801&0xFF=1, idx4→0x1006&0xFF=6). */
#define PROBE_MOD \
	"export let probe_table: [8]u16 = [0u16, 0x0800u16, 0x0801u16, " \
	"0x0803u16, 0x1006u16, 0x1009u16, 0x100Du16, 0x1812u16];\n"

static const struct row rows[] = {
	/* Indexed read on an imported (exported) [N]u16 at idx=0 — load-
	 * width fix: MOVZWQ reads the full u16 = 0x0000 → exit 0. */
	{ "mod_u16_idx0",
	  "package main;\n"
	  "import wcmodarr;\n"
	  "export fn main() i32 = {\n"
	  "	let v: u32 = (wcmodarr.probe_table[0]: u32);\n"
	  "	return v: i32;\n"
	  "};\n", "wcmodarr", PROBE_MOD, 0 },
	/* Nontrivial idx — pre-fix segfault repro. table[2] = 0x0801;
	 * 0x0801 mod 256 = 1. */
	{ "mod_u16_idx2",
	  "package main;\n"
	  "import wcmodarr;\n"
	  "export fn main() i32 = {\n"
	  "	let v: u32 = (wcmodarr.probe_table[2]: u32);\n"
	  "	return v: i32;\n"
	  "};\n", "wcmodarr", PROBE_MOD, 1 },
	/* Further idx — pins per-element stride. table[4] = 0x1006;
	 * 0x1006 mod 256 = 6. */
	{ "mod_u16_idx4",
	  "package main;\n"
	  "import wcmodarr;\n"
	  "export fn main() i32 = {\n"
	  "	let v: u32 = (wcmodarr.probe_table[4]: u32);\n"
	  "	return v: i32;\n"
	  "};\n", "wcmodarr", PROBE_MOD, 6 },
	/* Local-array control: confirms the existing IDENT-base path is
	 * unchanged by the #128b cgindex edit. */
	{ "local_arr_control",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: [4]u16 = [10u16, 20u16, 30u16, 40u16];\n"
	  "	let v: u32 = (a[2]: u32);\n"
	  "	return v: i32;\n"
	  "};\n", NULL, NULL, 30 },
	/* Same-package (NOT module-qualified) access — pins the in-package
	 * IDENT path stays unchanged; uses a local table. */
	{ "local_u16_idx_nonzero",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let t: [8]u16 = [0u16, 0x0800u16, 0x0801u16, 0x0803u16, "
	  "0x1006u16, 0x1009u16, 0x100Du16, 0x1812u16];\n"
	  "	let v: u32 = (t[2]: u32);\n"
	  "	return v: i32;\n"
	  "};\n", NULL, NULL, 1 },
	{ NULL, NULL, NULL, NULL, 0 }
};

static int
slurp_eq(const char *a, const char *b)
{
	FILE *fa = fopen(a, "rb");
	FILE *fb = fopen(b, "rb");
	if (!fa || !fb) { if (fa) fclose(fa); if (fb) fclose(fb); return -1; }
	int rc = 0;
	for (;;) {
		int ca = fgetc(fa);
		int cb = fgetc(fb);
		if (ca != cb) { rc = -1; break; }
		if (ca == EOF) break;
	}
	fclose(fa); fclose(fb);
	return rc;
}

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";
	char absbin[1024];
	if (bin[0] != '/') {
		char cwd[1024];
		if (getcwd(cwd, sizeof cwd) == NULL) return 1;
		snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
		bin = absbin;
	}

	char w6c[1100], w6c_ww[1100];
	snprintf(w6c, sizeof w6c, "%s/w6c", bin);
	snprintf(w6c_ww, sizeof w6c_ww, "%s/w6c_ww", bin);
	if (access(w6c_ww, X_OK) != 0) {
		fprintf(stderr, "modarridx: w6c_ww missing — cannot run "
		    "the cs==ww byte-id gate (the whole point of this test)\n");
		return 1;
	}

	int n = 0, fail = 0;
	for (int i = 0; rows[i].src; i++, n++) {
		char tmpdir[96];
		snprintf(tmpdir, sizeof tmpdir, "/tmp/wwmoda_%d_d_%d",
		    getpid(), i);
		mkdir(tmpdir, 0755);

		char src[160];
		snprintf(src, sizeof src, "%s/main915.ww", tmpdir);
		FILE *f = fopen(src, "wb");
		if (f == NULL) { fail++; rmdir(tmpdir); continue; }
		fputs(rows[i].src, f);
		fclose(f);

		char cmd[2048];
		/* Exported-probe-table package lives at <tmpdir>/<mod>/<mod>.ww
		 * so the sep dep-scan (rooted at the entry's dir) resolves the
		 * `import <mod>;`. */
		if (rows[i].modname != NULL) {
			char moddir[224], modf[320];
			snprintf(moddir, sizeof moddir, "%s/%s", tmpdir,
			    rows[i].modname);
			mkdir(moddir, 0755);
			snprintf(modf, sizeof modf, "%s/%s.ww", moddir,
			    rows[i].modname);
			FILE *mf = fopen(modf, "wb");
			if (mf == NULL) {
				fail++;
				snprintf(cmd, sizeof cmd, "rm -rf %s", tmpdir);
				(void)runwait(cmd);
				continue;
			}
			fputs(rows[i].modsrc, mf);
			fclose(mf);
		}

		/* #93 sep layout: build via `--sep -o <stem>` (the exported
		 * probe table links across packages under separate compilation);
		 * WW_PKGCACHE pinned under tmpdir. */
		char stem[200];
		snprintf(stem, sizeof stem, "%s/main915", tmpdir);
		snprintf(cmd, sizeof cmd,
		    "cd %s && WW_PKGCACHE=%s/pkgc %s/ww build --sep -o %s %s "
		    ">/dev/null 2>&1", tmpdir, tmpdir, bin, stem, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: cstage build failed\n",
			    rows[i].label);
			fail++;
			snprintf(cmd, sizeof cmd, "rm -rf %s", tmpdir);
			(void)runwait(cmd);
			continue;
		}

		int got = runwait(stem);
		if (got != rows[i].want_exit) {
			fprintf(stderr, "row[%s]: cstage exit %d, want %d\n",
			    rows[i].label, got, rows[i].want_exit);
			fail++;
		}

		/* Byte-id leg — bare w6c vs w6c_ww (the compiler binaries, NOT
		 * the driver, so layout-invariant). Only single-file rows can be
		 * fed standalone; the module rows' runtime exit IS their gate
		 * (+ the 994 bootstrap corpus for the cross-stage byte-id). */
		if (rows[i].modname == NULL) {
			char cs_s[200], ws_s[200];
			snprintf(cs_s, sizeof cs_s, "%s/cs.s", tmpdir);
			snprintf(ws_s, sizeof ws_s, "%s/ww.s", tmpdir);
			snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null",
			    w6c, cs_s, src);
			if (runwait(cmd) != 0) {
				fprintf(stderr, "row[%s]: w6c failed\n",
				    rows[i].label);
				fail++;
			} else {
				snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null",
				    w6c_ww, ws_s, src);
				if (runwait(cmd) != 0) {
					fprintf(stderr, "row[%s]: w6c_ww failed\n",
					    rows[i].label);
					fail++;
				} else if (slurp_eq(cs_s, ws_s) != 0) {
					fprintf(stderr,
					    "row[%s]: cstage/wwstage .s DIFFER "
					    "(rule-10 byte-id violation)\n",
					    rows[i].label);
					fail++;
				}
			}
		}

		snprintf(cmd, sizeof cmd, "rm -rf %s", tmpdir);
		(void)runwait(cmd);
	}

	if (fail) {
		fprintf(stderr, "%d/%d mod-arr-idx tests failed\n", fail, n);
		return 1;
	}
	printf("modarridx: %d/%d ok (cstage run + cs==ww byte-id)\n",
	    n, n);
	return 0;
}